skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: A Microwave Sensor Array for Water Quality Testing
Improved data acquisition with autonomous sensor networks for fine-grained data sampling and collection is critical for ensuring urban water sustainability. It leads to better analysis, predictability, and optimization of water resources. To address this need, here, we propose a microwave sensor array composed of five complementary split ring resonators (CSRRs) operating in the frequency range of 1 GHz to 10 GHz. The use of an array provides the opportunity to acquire more information regarding the water pollutants. Here, the design of the proposed sensor array is presented along with the results of testing that with water samples with heavy metal pollutants including Chromium (Cr), Lead (Pb), and Mercury (Hg).  more » « less
Award ID(s):
1841558
PAR ID:
10192244
Author(s) / Creator(s):
; ; ;
Date Published:
Journal Name:
2019 IEEE 20th Wireless and Microwave Technology Conference (WAMICON)
Page Range / eLocation ID:
1 to 4
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. The CO Mapping Array Project (COMAP) is a carbon monoxide (CO) line intensity mapping experiment using a 19-feed 26–34 GHz focal plane spectrometer array on a 10.4 m dish at the Owens Valley Radio Observatory. We are developing a water vapor radiometer (WVR) that continuously measures the temporal variability of the atmosphere’s water vapor content along the telescope’s line of sight to better calibrate the COMAP science data. The WVR is designed to monitor the rotational transition line of water vapor around 22.2 GHz, with a spectral measurement between 18 and 26 GHz and a measurement of continuum at 28–30 GHz. Here we describe the COMAP WVR instrument system. 
    more » « less
  2. Natural and anthropogenic activities result in the production of polycyclic aromatic hydrocarbons (PAHs), persistent pollutants that negatively impact the environment and human health. Rapid and reliable methods for the detection and discrimination of these compounds remains a technological challenge owing to their relatively featureless properties, structural similarities, and existence as complex mixtures. Here, we demonstrate that the inner filter effect (IFE), in combination with conjugated polymer (CP) array-based sensing, offers a straightforward approach for the quantitative and qualitative profiling of PAHs. The sensor array was constructed from six fluorescent fluorene-based copolymers, which incorporate side chains with peripheral 2-phenylbenzimidazole substituents that provide spectral overlap with PAHs and give rise to a pronounced IFE. Subtle structural differences in copolymer structure result in distinct spectral signatures, which provide a unique “chemical fingerprint” for each PAH. The discriminatory power of the array was evaluated using linear discriminant analysis (LDA) and principal component analysis (PCA) in order to discriminate between 16 PAH compounds identified as priority pollutants by the US Environmental Protection Agency (EPA). This array is the first multivariate system reliant on the modulation of the spectral signatures of CPs through the IFE for the detection and discrimination of closely related polynuclear aromatic species. 
    more » « less
  3. This paper presents a magnetic sensor based autotracking method for a phased array based wireless power transfer system to be implemented in neuromodulation applications. This method is proposed to track the position of the receiver(placed on a freely moving animal) and transmit the microwave signal with a focused beam to the target receiver. The coordinate locations of the target are obtained from the magnetic sensor and converted into phase information for the phased array. The system is constructed by a 2.4 GHz near-field 4×4 phased array transmitter antenna with 4-bit phase shifters. The phased array TX antenna steers the beam from -5° to -155° in the θ plane. The magnetic sensor can detect the location of the receiver and the in this steering range. The process of tracking the the target and focusing the beam has been evaluated by simulation. 
    more » « less
  4. The Haystack Telescope is an antenna with a diameter of 37 m and an elevation-dependent surface accuracy of ≤100μm that is capable of millimeter-wave observations. The radome-enclosed instrument serves as a radar sensor for space situational awareness, with about one-third of the time available for research by MIT Haystack Observatory. Ongoing testing with the K-band (18–26 GHz) and W-band receivers (currently 85–93 GHz) is preparing the inclusion of the telescope into the Event Horizon Telescope (EHT) array and the use as a single-dish research telescope. Given its geographic location, the addition of the Haystack Telescope to current and future versions of the EHT array would substantially improve the image quality. 
    more » « less
  5. Abstract Metal cations are potent environmental pollutants that negatively impact human health and the environment. Despite advancements in sensor design, the simultaneous detection and discrimination of multiple heavy metals at sub‐nanomolar concentrations in complex analytical matrices remain a major technological challenge. Here, the design, synthesis, and analytical performance of three highly emissive conjugated polyelectrolytes (CPEs) functionalized with strong iminodiacetate and iminodipropionate metal chelates that operate in challenging environmental samples such as seawater are demonstrated. When coupled with array‐based sensing methods, these polymeric sensors discriminate among nine divalent metal cations (CuII, CoII, NiII, MnII, FeII, ZnII, CdII, HgII, and PbII). The unusually high and robust luminescence of these CPEs enables unprecedented sensitivity at picomolar concentrations in water. Unlike previous array‐based sensors for heavy metals using CPEs, the incorporation of distinct π‐spacer units within the polymer backbone affords more pronounced differences in each polymer's spectroscopic behavior upon interaction with each metal, ultimately producing better analytical information and improved differentiation. To demonstrate the environmental and biological utility, a simple two‐component sensing array is showcased that can differentiate nine metal cation species down to 500 × 10−12 min aqueous media and to 100 × 10−9 min seawater samples collected from the Gulf of Mexico. 
    more » « less